Am I being selfish?

I am 2 weeks postpartum after a c section with a newborn and my SO is home for 6 weeks to help with me, baby, and his 2 kids. Well, he’s been leaving or doing stuff every single day since we’ve been home. He’s the kind of person that can’t sit around and be bored or he gets super moody and impossible to deal with. Anyway, his 6 year old woke up this morning not feeling well and been puking all morning but my SO has been outside working in the garage while im juggling a hungry newborn and diaper changes, and pumping along with a 6 year old who has now puked on the couch 3 times and I have a weak stomach when it comes to other peoples vomit. Now I’m worried that my newborn will catch whatever he has. Am I in the wrong for being irritated that I’ve been left inside to deal with all this by myself? There’s no actual reason that he can’t be in here helping me with the kids...